Long-term outcomes mixed for bioresorbable scaffold vs. metallic stent: ABSORB IV
Key takeaways:
- There were small increases in target lesion failure and device thrombosis within 3 years with a bioresorbable scaffold vs. drug-eluting stents.
- Events between 3 and 5 years were similar between the groups.
Compared with metallic drug-eluting stents, a first-generation everolimus-eluting bioresorbable vascular scaffold had similar 5-year rates of death, patient-oriented composite events, angina recurrence and quality of life, data show.
However, the everolimus-eluting bioresorbable vascular scaffold (BVS; Absorb, Abbott) was associated with slightly increased rates of target lesion failure and device thrombosis compared with metallic DES during the first 3 years prior to complete bioresorption, according to Gregg W. Stone, MD, director of academic affairs for the Mount Sinai Heart Health System and professor of medicine and population health sciences and policy at the Zena and Michael A. Wiener Cardiovascular Institute at the Icahn School of Medicine at Mount Sinai.
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Stone presented long-term data from the blinded ABSORB IV trial, in which operators used an optimal technique in appropriately sized coronary arteries, at EuroPCR. The data were simultaneously published in the Journal of the American College of Cardiology.
BVS were designed to improve late event-free survival compared with metallic DES; however, initial trials demonstrated worse early outcomes with BVS, in part due to suboptimal technique, Stone said during a late-breaking clinical trial presentation.
“Early studies with the Absorb [poly(L-lactide)]-based everolimus-eluting BVS [Abbott] demonstrated increased rates of scaffold thrombosis and target lesion failure [TLF] compared with metallic cobalt chromium everolimus-eluting stents [EES], in part due to suboptimal implantation technique, leading to the development and validation of the [predilation, sizing and postdilation] technique,” Stone said. “The blinded ABSORB IV trial is the largest randomized controlled trial to date and enrolled an expanded patient population with BVS implanted with improved technique. To date, only the 1-year results have been published.”
Study design
Stone and colleagues analyzed data from 2,604 patients from 147 sites with acute and chronic coronary syndromes with one to three target lesions with visually assessed lesion length of less than 24 mm and a reference vessel diameter between 2.5 and 3.75 mm. Researchers randomly assigned patients to receive the Absorb BVS (n = 1,296) with the improved technique or the cobalt chromium EES (n = 1,308) and followed the cohort for 5 years. Patients and post-cath lab health care and research personnel were blinded to allow for assessment of angina and quality of life, measured continuously via the Seattle Angina Questionnaire-7 and the EuroQOL-5D Visual Analog Scale. The primary endpoint was TLF at 30 days, powered for noninferiority.
Initial data previously reported by Healio demonstrated that at 30 days, TLF occurred in 5% of patients assigned the BVS vs. 3.7% assigned the EES (risk difference = 1.3%; upper 97.5% confidence limit, 2.89; P for noninferiority = .0244). At 1 year, this outcome was seen in 7.8% in the BVS group compared with 6.4% in the EES group (risk difference = 1.4%; upper 97.5% confidence limit, 3.4; P for noninferiority = .0006).
Similar 5-year outcomes
At 5 years, TLF occurred in 17.5% of patients assigned to BVS and 14.5% of patients assigned to EES, a 3% absolute difference (HR = 1.24; 95% CI, 1.02-1.52; P = .03). Device thrombosis within 5 years occurred in 1.7% of BVS patients and 1.1% of EES patients (HR = 1.65; 95% CI, 0.82-3.29; P = .15). TLR rates were slightly greater with BVS than EES through 3-year follow-up (HR = 1.32; 95% CI, 1.05-1.65; P = .03) and similar between 3 and 5 years (HR = 1.03; 95% CI, 0.71-1.49; P = .89), and the same was true for device thrombosis, Stone said.
Angina, which was centrally adjudicated, recurred within 5 years in 659 patients — a cumulative rate of 53% — assigned to BVS and in 53.3% of patients assigned to EES (HR = 0.97; 95% CI, 0.88-1.08; P = .63). Conversely, the rates of typical angina or anginal equivalent symptoms measured at any discrete time point were less than 10% in both groups.
At 5 years, there was no significant difference between the two groups in death or overall CV events. Both groups had a similar quality of life.
In the study, the researchers noted that improved patient and lesion selection, especially the near-elimination of lesions with reference vessel diameter < 2.25 mm, the leading cause of adverse outcomes with the Absorb BVS in prior trials, as well as the optimized technique, were likely responsible for the improved results.
As Healio previously reported, the FDA approved Absorb BVS in 2016, but the company voluntarily stopped manufacturing due to low commercial sales. Development of future generations of the product continue.
References:
- Stone GW, et al. J Am Coll Cardiol. 2023;doi:10.1016/j.jacc.2023.05.003.
- Stone GW, et al. Lancet. 2018;doi:10.1016/S0140-6736(18)32283-9.
Collapse
Stone GW, et al. Late-breaking clinical data: Focus on stent technology. Presented at: EuroPCR; May 16-19, 2023; Paris (hybrid meeting).
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